HTTP streaming specifications, such as the HTTP Live Streaming specification by Apple Inc. of Cupertino, Calif. and the HTTP Dynamic Streaming specification by Adobe Systems Inc. of San Jose, Calif., describe architectures for providing on-demand and live video streaming to internet-connected devices.
In general, HTTP streaming specifications describe internet-connected devices as receiving audio and video as a sequence of segmented media files. For example, to begin playback of a stream, an internet-connected device fetches a manifest file (e.g., playlist file, index file) from a server system, which can include a base uniform resource locator (URL) or a sequence of uniform resource identifiers (URIs) that identify the locations of consecutive segmented media files of the stream. The client then downloads the segmented media files identified in the manifest file, and begins presenting the stream to a user of the internet-connected device. To accommodate live broadcasts, the internet-connected device can periodically fetch and load new versions of the manifest file, which include URIs that identify the locations of new segmented media files of the live stream. In this manner, a sequence of manifest files can be created to accommodate live broadcasts, where media segment files are continually being produced.
Conventional streaming systems that implement the above HTTP streaming specifications typically include a media encoder and stream segmenter. The media encoder encodes the prerecorded content or live broadcasts into a video transport stream, which is then broken into segmented media files by the stream segmenter. The stream segmenter also creates the manifest files, which include a sequence of URIs that identify consecutive segmented media files of the stream. However, at this time there is no mechanism for inserting URIs or replacing URIs in the manifest files created by the stream segmenter with URIs that identify targeted media files, such as, advertisement media files, news or weather alert media files or other user-targeted types of media files.